Deficiency & Toxicity

What is a nutrient deficiency? When it comes to high performance plant nutrients, finding the “sweet spot” for your particular varietals can be quite the balancing act. How much is too much? How much is enough? While these factors are greatly influenced by key variables such as environment and genetics, etc., knowing how to spot particular symptoms of nutrient deficiency or excess can help save an entire crop from impending failure. Growers beware, nutrient problems are not always as they seem! There are many potential causes for both deficiencies and toxicities. Just because it looks like a deficiency, doesn’t mean your not providing enough nutrition. It may simply be an incorrect pH causing an elemental lockout, or perhaps the nutrient in your reservoir is overdue for a change. Remember to exhaust all avenues before ascertaining causality. The first thing to do is drain all nutrient solution from your system and flush all root zones with 1/3 strength nutrient solution pH balanced to suit your style of growing. Quite often, the easy fix is a foliar spray of a complete fertilizer, however if the problem still exists in the root zone, you’ll need to resolve it, as foliar spraying is only a band-aid approach to rectifying a root based disorder.

Below are 14 essential nutrients (aside from carbon, oxygen, and hydrogen), vital for many aggressively-feeding varietals: 

Primary Macro-Nutrients:

  • Nitrogen (N)
  • Phosphorus (P)
  • Potassium (K)

Secondary Macro-Nutrients:

  • Calcium (Ca)
  • Magnesium (Mg)
  • Sulfur (S)

Micro-Nutrients:

  • Iron (Fe)
  • Manganese (Mn)
  • Copper (Cu)
  • Zinc (Zn)
  • Boron (B)
  • Molybdenum (Mo)
  • Chloride (Cl-)
  • Silicon (Si)

In the following, we will explore each of these key nutrients, their role/function within the plant and learn how to discern symptoms of toxicity and deficiency, as well as options for rectification.

PRIMARY MACRO-NUTRIENTS

NITROGEN

Functions of Nitrogen in Plants:

  • Comprises all amino acids.
  • Component of nucleic acids - the building blocks for DNA.
  • Necessary for proper photosynthesis, as it comprises chlorophyll.
  • Required for proper thylakoid (i.e. photosynthesis) function.
  • Building block for many proteins and enzymes necessary to plants.
  • An integral atomic component needed to bond with magnesium in the formation of chlorin-magnesium ligands (i.e. chlorophyll molecules).
  • Enzymes and isoenzymes assimilate nitrogen in the biosynthesis of amino acids and nucleic acids, eventually assembled into various proteins.
  • Various defense compounds require nitrogen as an atomic component, bolstering plant defenses against abiotic and biotic stress.

Nitrogen Deficiency

Being a mobile nutrient, nitrogen is allocated from older plant tissue to younger growth when in a deficient state. Signs of nitrogen deficiency begin in the lower, older growth with leaves in this area turning light green to yellow. New growth is still green - with necrosis on older foliage beginning at the leaf tips and moving inward. How do I correct a nitrogen deficiency? Correcting a nitrogen deficiency is rather simple - increase the amount of available nitrogen to the plant. This can be achieved either through root feed and/or foliar application of a fertilizer with adequate water soluble nitrogen, e.g. Commercial Edition Micro nutrient or Cal-Mag, ensuring that the root zone pH is within the appropriate range for the particular system utilized (hydroponics, soil, etc.). As a side note, foliar spraying will correct a deficiency faster than root feeding - however, you must still address the cause of the deficiency within the root zone, be it an incorrect pH issue, or perhaps an unbalanced fertilizer formula.

Nitrogen Toxicity

In an excessive state, foliage starts to turn very dark green, with stems becoming very stiff and brittle. In this toxic state, plants are much more susceptible to pathogenic attack. How do I correct nitrogen toxicity? If nitrogen toxicity is the issue, flush root zone media with a 1/3 strength nutrient solution and then resume feeding with a more dilute/weaker mixture (approximately 3/4 strength) until problem is resolved. All Commercial Edition nutrient formulations are well-balanced and will provide exacting elemental ratios to the plant if used as directed.

PHOSPHORUS

Functions of Phosphorus in Plants:

  • Facilitates reproductive development and healthy root growth.
  • Critical building block for nucleic acids - essential for DNA production.
  • Vital in nearly every energy transfer role within the plant, generally as ADP or ATP (adenosine diphosphate and adenosine triphosphate, respectively) - these energy-transfer molecules are captured during the photosynthesis of simple sugars.
  • Reduces the formation of carboxylate exudates through the suppression of cluster root formation, greatly reducing carbon usage and pH fluctuations.
  • Drought tolerance is markedly increased with exposure to adequate phosphorus levels, due to the larger leaf area, deeper root systems, and decreased stomatal sensitivity.

Phosphorus Deficiency

Also being a mobile nutrient, phosphorus is translocated from older plant tissue to younger growth when in a deficient state. Symptoms of phosphorus deficiency initially begin as a dark green to grey and shiny appearance on older leaf tissue followed by brown or purple splotching. The leaves will begin to exhibit a dry and thick nature, with stems purpling. Eventually, leaves will turn yellow and die if left untreated. How do I correct a phosphorus deficiency? Correcting a phosphorus deficiency is also rather simple increase the amount of available phosphorus to the plant. This can be achieved through root feed and/or foliar application of a water-soluble phosphoric containing product,e.g. Commercial Edition Bloom nutrient, ensuring that the pH is within the appropriate range for the particular system utilized (hydroponics, soil, etc.). As a side note, foliar spraying will correct a deficiency faster than root feeding - however, you must still address the cause of the deficiency within the root zone, be it an incorrect pH issue, or perhaps an unbalanced fertilizer formula.

Phosphorus Toxicity

Phosphorus toxicity is quite rare and generally, in excessive amounts, will begin to alter the absorption of copper and zinc - this can give the false impression of copper or zinc deficiencies that are both explained later. How do I correct phosphorus toxicity? If phosphorus toxicity is the issue, flush root zone media with a 1/3 strength nutrient solution and then resume feeding with a more dilute/weaker mixture (approximately 3/4 strength) until problem is resolved. All Commercial Edition nutrient formulations are well-balanced and will provide exacting elemental ratios to the plant if used as directed.

POTASSIUM

Functions of Potassium in Plants:

  • Regulates the rate of photosynthesis.
  • Facilitates over 60 important enzymatic reactions within the plant.
  • Necessary for protein and starch synthesis and optimizes sugar transport.
  • A critical component for the regulation of osmotic gradients and membrane electrical potential between cells - exchanged in the polarization/depolarization of cells for the transport of water and nutritive ions.
  • Heavily involved in electrical neutralization of inorganic and organic anions and macromolecules.
  • Directly affects the turgidity or flaccidity of guard cells surrounding stomata - regulating the opening and closing of this integral gas-exchange pore.
  • Required for the production of carbohydrates and starches - directly increasing dry plant weight and yield.

Potassium Deficiency

Much like nitrogen and phosphorus, potassium is also considered a mobile nutrient. While generally symptoms will appear on lower older growth, potassium problems are also known to make themselves apparent in newer growth. In a deficient state, symptoms are much like that of nutrient burn with leaf edges turning brown and appearing “burnt” - difference here being a yellowing in the leaf margins and noticeable stretching of weak stems. Eventually, leaf tips will curl downwards as necrosis sets in. This deficiency is quite commonly mistaken for other problems such as light burn/bleach and nutrient burn. How do I correct a potassium deficiency? Correcting a potassium deficiency is easily rectified - increase the amount of available potassium to the plant. This can be achieved through root feed and/or foliar application of a water-soluble potassium-containing fertilizer, e.g. Commercial Edition Bloom nutrient ensuring that the pH is within the appropriate range for the particular system utilized (hydroponics, soil, etc.). As a side note, foliar spraying will correct a deficiency faster than root feeding - however, you must still address the cause of the deficiency within the root zone, be it an incorrect pH issue, or perhaps an unbalanced fertilizer formula.

Potassium Toxicity

Rarely is potassium encountered in a toxic state, much like phosphorus. In an excessive state, potassium can interfere with magnesium, iron, zinc, and manganese uptake by plants - leading to the false assumption of a deficient state of these other nutrients. How do I correct potassium toxicity? If potassium toxicity is the issue, flush root zone media with a 1/3 strength nutrient solution and then resume feeding with a more dilute/weaker mixture (approximately 3/4 strength) until problem is resolved. All Commercial Edition nutrient formulations are well-balanced and will provide exacting elemental ratios to the plant if used as directed.

SECONDARY MACRO-NUTRIENTS

CALCIUM

Functions of Calcium in Plants:

  • Critical for many hormonal and enzymatic processes within the plant.
  • Critical for strengthening cell walls and facilitates proper cell elongation.
  • Important in heat stress protection (optimizes stomata functioning and needed for heat stress protein production).
  • Closely tied with biotic and abiotic stress signaling within the plant - cytosolic calcium concentrations have been shown to directly influence general stress-related signals through complexes such as depolarization-activated and voltage-independent cation channels.
  • Calcium-dependent protein kinases within the plant synthesize defense-related compounds, cued by particular environmental disturbances.
  • Serves as an important counter‐cation for inorganic and organic anions in the vacuole, allowing for ionic transport.
  • Necessary for cross-linking acidic pectin residues within the cell wall - causing an increase in cell rigidity, strength and weight.

Calcium Deficiency

Generally regarded as an immobile nutrient, calcium cannot be translocated from older plant tissues to newer growth, resulting in symptomatic appearance of deficiency on the new growth of plants. A deficient state can also cause symptoms to appear on new fan leaves that are exposed to light, showing brown mottling/rusting and crinkling. If allowed to persist, new growth becomes severely stunted and stems become hollow and brittle. Another tell-tale sign of calcium deficiency is that the plant’s drought tolerance is markedly reduced. How do I correct a calcium deficiency? Correcting a calcium deficiency is straightforward - increase the amount of available calcium to the plant. This can be achieved through root feed and/or foliar application of a water-soluble calcium-containing product, e.g. Commercial Edition Micro nutrient or Cal-Mag, ensuring that the pH is within the appropriate range for the particular system utilized (hydroponics, soil, etc.). As a side note, foliar spraying will correct a deficiency faster than root feeding - however, you must still address the cause of the deficiency within the root zone, be it an incorrect pH issue, or perhaps an unbalanced fertilizer formula.

Calcium Toxicity

Identification of calcium toxicity is much more difficult to identify visually, but since excessive calcium can lock out potassium and magnesium, a deficiency of these other nutrients is a quick way to potentially diagnose excessive calcium. How do I correct calcium toxicity? If calcium toxicity is the issue, flush root zone media with a 1/3 strength nutrient solution and then resume feeding with a more dilute/weaker mixture (approximately 3/4 strength) until problem is resolved. All Commercial Edition nutrient formulations are well-balanced and will provide exacting elemental ratios to the plant if used as directed.

MAGNESIUM

Functions of Magnesium in Plants:

  • Increases the utilization of Iron.
  • Needed for amino acid and protein synthesis and is a key player in several enzymatic processes.
  • Remarkably necessary for the regulation of cell proliferation - as intracellular magnesium increases, protein synthesis becomes enhanced and with it the onset of DNA synthesis.
  • Strongly connected with calcium - almost synergistic, as cytosolic magnesium sensitizes slow vacuolar channels to physiological cytosolic calcium elevations.
  • Regulates the ionic balance in cells, particularly around the stomata to ensure proper opening and closing.
  • Being the central atom in chlorophyll molecules, photosynthesis and the activity of photosynthetic enzymes are heavily dependent upon a sufficient presence of magnesium.

Magnesium Deficiency

Crucial to photosynthesis, magnesium is the central building block essential for chlorophyll molecules. Being highly mobile, magnesium is able to be translocated from older plant tissues to newer growth. Because of this, magnesium-deficient symptoms appear first in the lower older growth as they begin to yellow from the edges inward, maintaining green interveinal space. As it progresses, edges begin to brown and curl; rusting spots may develop without wilting. How do I correct a magnesium deficiency? Correcting a magnesium deficiency is no sweat - increase the amount of available magnesium to the plant. This can be achieved through root feed and/or foliar application of a water-soluble magnesium-containing fertilizer, e.g. Commercial Edition Grow nutrient or Cal-Mag, ensuring that the pH is within the appropriate range for the particular system utilized (hydroponics, soil, etc.). As a side note, foliar spraying will correct a deficiency faster than root feeding - however, you must still address the cause of the deficiency within the root zone, be it an incorrect pH issue, or perhaps an unbalanced fertilizer formula.

Magnesium Toxicity

Much like the previously mentioned nutrients, magnesium in excess is quite rare. Diagnosing magnesium toxicity is quite difficult and is generally displayed as a calcium lock-out/deficiency. How do I correct magnesium toxicity? If magnesium toxicity is the issue, flush root zone media with a 1/3 strength nutrient solution and then resume feeding with a more dilute/weaker mixture (approximately 3/4 strength) until problem is resolved. All Commercial Edition nutrient formulations are well-balanced and will provide exacting elemental ratios to the plant if used as directed.

SULFUR

Functions of Sulfur in Plants:

  • Necessary for chlorophyll production.
  • Integral component of many enzymes, proteins, and peptides.
  • Necessary for the biosynthesis of nearly all plant proteins and some hormones, even antioxidant oligopeptides such as glutathione.
  • Detoxification of xenobiotics is regulated by sulfur-containing compounds - the thiol group’s nucleophilicity conjugates directly with sulfhydryl groups.
  • Plant defenses against pathogenic attacks are bolstered - sulfur-rich metabolites, such as glucosinolates, are responsible for the up-regulation of plant defense genes (i.e. NIT3 gene).

Sulfur Deficiency

Although being used primarily in the vegetative stage, sulfur is critical through a plant’s entire life cycle, particularly for root growth and protein synthesis. As an immobile nutrient, problems with this particular nutrient will be visible initially in newer growth. Starting at the back of the leaf near the petiole and moving outward to the apex, chlorosis (loss of greenness) becomes quite apparent in a sulfur-deficient state, accompanied by leaf stem purpling. How do I correct a sulfur deficiency? Correcting a sulfur deficiency is not difficult - simply increase the amount of available sulfur to the plant. This can be achieved through root feed and/or foliar application of a water-soluble sulfur-containing fertilizer, e.g. Commercial Edition Bloom nutrient, ensuring that the pH is within the appropriate range for the particular system utilized (hydroponics, soil, etc.). As a side note, foliar spraying will correct a deficiency faster than root feeding - however, you must still address the cause of the deficiency within the root zone, be it an incorrect pH issue, or perhaps an unbalanced fertilizer formula.

Sulfur Toxicity

In an excessive state, toxic symptoms arise in the form of dwarfed plants and nutrient-burn-like appearance (browning at the leaf tip). How do I correct sulfur toxicity? If sulfur toxicity is the issue, flush root zone media with a 1/3 strength nutrient solution and then resume feeding with a more dilute/weaker mixture (approximately 3/4 strength) until problem is resolved. All Commercial Edition nutrient formulations are well-balanced and will provide exacting elemental ratios to the plant if used as directed.

MICRO-NUTRIENTS

IRON

Functions of Iron in Plants:

  • Involved in chlorophyll production and required for lignin formation.
  • Critical for many enzymatic reactions and nitrogen reduction/fixation.
  • Required for the production of low-molecular weight proteins required for the assembly of Photosystem I - an integral membrane protein complex that utilizes light energy for the mediation of electron transfer from plastocyanin to ferredoxin.
  • Directly affects chlorophyll production through the regulation of the rate of δ-aminolevulinic acid synthesis.
  • Necessary for production of ferredoxin (an iron-sulfur protein) in chloroplasts - both cyclic and non-cyclic photophosphorylation reactions of photosynthesis utilize ferredoxin.

Iron Deficiency

While oftentimes experienced with other nutrient deficiencies, iron deficiency can be identified by new growth exhibiting a very light green hue - almost white. Since this particular nutrient is highly immobile, ferrous issues are experienced in the newer growth of most plants - a distinguishing feature to recognize the difference between magnesium and iron deficiency. The extremely light colored plant tissue can turn healthy green again with corrective action. How do I correct an iron deficiency? Correcting an iron deficiency is manageable - increase the amount of available iron to the plant. This can be achieved through root feed and/or foliar application of a water-soluble iron-containing fertilizer (preferably chelated iron), e.g. Commercial Edition Micro nutrient, Cal-Mag or Trich-XL, ensuring that the pH is within the appropriate range for the particular system utilized (hydroponics, soil, etc.). As a side note, foliar spraying will correct a deficiency faster than root feeding - however, you must still address the cause of the deficiency within the root zone, be it an incorrect pH issue, or perhaps an unbalanced fertilizer formula.

Iron Toxicity

Although a toxic state of iron is rare, when experienced, an iron toxicity can inhibit the uptake of phosphorus. This chlorosis is primarily interveinal and begins at the back of the leaf near the petiole. Identification of this toxic state can be observed in the form of light golden leaf tissue and brown mottling/spotting in the upper new growth. How do I correct iron toxicity? If iron toxicity is the issue, flush root zone media with a 1/3 strength nutrient solution and then resume feeding with a more dilute/weaker mixture (approximately 3/4 strength) until problem is resolved. All Commercial Edition nutrient formulations are well-balanced and will provide exacting elemental ratios to the plant if used as directed.

MANGANESE

Functions of Manganese in Plants:

  • Involved in respiration reactions.
  • Important activator for several enzymes in the tricarboxylic acid cycle.
  • Needed for proper nitrogen metabolism and required for several enzymatic reactions.
  • Involved in the regulation of oxidative stress genes via peroxide regulator modulation.
  • Crucial for reactions in Photosystem II - involved in water-splitting and the subsequent evolution of oxygen in photosynthesis.

Manganese Deficiency

Similar to iron, manganese is quite immobile and does not translocate readily throughout plant tissues. Because of this, problems with this particular nutrient are seen initially in new growth. Interveinal chlorosis begins to dominate the upper new growth followed by brown mottling/spotting. This state progresses with dead spots on leaves and overall plant growth is sharply stunted. How do I correct a manganese deficiency? Correcting a manganese deficiency is simple - increase the amount of available manganese to the plant. This can be achieved through root feed and/or foliar application of a water-soluble manganese-containing fertilizer, e.g. Commercial Edition Micro nutrient or Trich-XL, ensuring that the pH is within the appropriate range for the particular system utilized (hydroponics, soil, etc.). As a side note, foliar spraying will correct a deficiency faster than root feeding - however, you must still address the cause of the deficiency within the root zone, be it an incorrect pH issue, or perhaps an unbalanced fertilizer formula.

Manganese Toxicity

In an excessive state, manganese becomes apparent on new growth as dark orange to brown mottling. Iron and zinc deficiency-like symptoms may also be displayed in a toxic state, as excessive manganese greatly affects these ions. How do I correct manganese toxicity? To rectify manganese toxicity, flush root zone media with a 1/3 strength nutrient solution and then resume feeding with a more dilute/weaker mixture (approximately 3/4 strength) until problem is resolved. All Commercial Edition nutrient formulations are well-balanced and will provide exacting elemental ratios to the plant if used as directed.

COPPER

Functions of Copper in Plants:

  • Heavily involved in the synthesis of lignin.
  • Required for nitrogen and carbohydrate metabolism.
  • Essential for chlorophyll production and serves as a photosynthetic catalyst.
  • Involved heavily in photosynthetic and respiratory electron transport chains.
  • Critical for the formation of several important enzymes, including polyphenol oxidase.
  • Copper results in a lower ratio of chlorophyll a to b and fluorescence induction transients, showing accelerated Photosystem II closure - this means greater light-harvesting abilities by photosynthetic tissues.

Copper Deficiency

While copper is relatively immobile within plant tissue, a deficient state becomes most apparent on the leaf tissue directly under lighting and leaf chlorosis becomes visual on leaf tips and edges. This is strongly juxtaposed by the rest of the leaf tissue turning quite dark - black, blue, and purple are all colors exhibited. Overall appearance of leaf tissue is quite stiff and almost metallic in sheen. Both male and female reproductive functions are greatly hindered in this state, as copper is critical through a variety of reproductive processes. How do I correct a copper deficiency? Correcting a copper deficiency is simple - increase the amount of available copper to the plant. This can be achieved through root feed and/or foliar application of a water-soluble copper-containing fertilizer, e.g. Commercial Edition Micro nutrient or Trich-XL, ensuring that the pH is within the appropriate range for the particular system utilized (hydroponics, soil, etc.). As a side note, foliar spraying will correct a deficiency faster than root feeding - however, you must still address the cause of the deficiency within the root zone, be it an incorrect pH issue, or perhaps an unbalanced fertilizer formula.

Copper Toxicity

In an excessive state, copper will start to decay plants quickly - initial symptoms appear as unnaturally large roots and severe leaf chlorosis progressing to eventual necrosis and death. How do I correct copper toxicity? To rectify copper toxicity, flush root zone media with a 1/3 strength nutrient solution and then resume feeding with a more dilute/weaker mixture (approximately 3/4 strength) until problem is resolved. All Commercial Edition nutrient formulations are well-balanced and will provide exacting elemental ratios to the plant if used as directed.

ZINC

Functions of Zinc in Plants:

  • Mediates cold-weather response and resistance.
  • Required for production of auxins - endogenous plant growth hormones.
  • Essential for proper carbohydrate metabolism and chlorophyll production.
  • Closely tied with the regulation of root exudation of amino acids and organic acid anions.
  • Necessary for production and function of specific DNA-binding proteins, called zinc fingers.
  • Regulates the activity of several enzymes involved in the detoxification of membrane-damaging oxy-radicals.

Zinc Deficiency

Even though zinc is considered a mobile nutrient, a deficient state is observed in new growth of most plants. In the newer growth, zinc deficiency makes itself noticeable through leaf tissue chlorosis, followed by very wispy and narrow leaf growth. In this state, growth is stunted markedly and leaf tips begin to turn dark and necrotic. How do I correct a zinc deficiency? Correcting a zinc deficiency is manageable - simply increase the amount of available zinc to the plant. This can be achieved through root feed and/or foliar application of a water-soluble zinc-containing fertilizer, e.g. Commercial Edition Micro nutrient or Trich-XL, ensuring that the pH is within the appropriate range for the particular system utilized (hydroponics, soil, etc.). As a side note, foliar spraying will correct a deficiency faster than root feeding - however, you must still address the cause of the deficiency within the root zone, be it an incorrect pH issue, or perhaps an unbalanced fertilizer formula.

Zinc Toxicity

In an excessive state, zinc has the ability to kill many plants rather quickly. Generally, a toxic state of zinc interferes greatly with iron absorption - this specific toxicity appears as an iron deficiency that progresses extremely rapidly. How do I correct zinc toxicity? To rectify zinc toxicity, flush root zone media with a 1/3 strength nutrient solution and then resume feeding with a more dilute/weaker mixture (approximately 3/4 strength) until problem is resolved. All Commercial Edition nutrient formulations are well-balanced and will provide exacting elemental ratios to the plant if used as directed.

BORON

Functions of Boron in Plants:

  • Required for cell wall structure - works with calcium on this function.
  • Needed for proper cell division and regulates various plant hormones.
  • Mediates the transport rate of sugars produced from photosynthesis.
  • Involved in redox and ion transport reactions through the stimulation of various enzymes, particularly nicotinamide adenine dinucleotide (NAD) and its reduced oxidase (NADH).
  • By bridging hydroxyl groups on several ligands that comprises the cell wall and plasma membrane (i.e. glycoproteins, glycolipids, etc.), boron plays quite a structural role in plant development and strength.
  • Regulates the expression of genes involved in membrane structure and function, such as AGP genes responsible for arabidogalactan proteins that serve as binding anchors to surface proteins (i.e. glycosyl-phosphatidyl-inositol) on the cell wall.

Boron Deficiency

Deficiencies of boron are generally quite rare, however, when experienced are usually observed alongside other nutrient deficiencies, particularly calcium. Being immobile by nature, boron deficiencies are observed most in the newer growth. This is exhibited by greatly reduced new growth that begins to twist and curl, eventually becoming necrotic. A lack of boron will eventually kill most plants, causing all new growth to halt and old growth begins to become necrotic and completely fall off. How do I correct a boron deficiency? Correcting a boron deficiency is easy - increase the amount of available boron to the plant. This can be achieved through root feed and/or foliar application of a water-soluble boron-containing fertilizer, e.g. Commercial Edition Micro nutrient or Trich-XL, ensuring that the pH is within the appropriate range for the particular system utilized (hydroponics, soil, etc.). As a side note, foliar spraying will correct a deficiency faster than root feeding - however, you must still address the cause of the deficiency within the root zone, be it an incorrect pH issue, or perhaps an unbalanced fertilizer formula.

Boron Toxicity

Although an excessive state is rare, when encountered leaf tip chlorosis becomes apparent - similar to traditional nutrient burn (which it is easily confused with). How do I correct boron toxicity? To rectify boron toxicity, flush root zone media with a 1/3 strength nutrient solution and then resume feeding with a more dilute/weaker mixture (approximately 3/4 strength) until problem is resolved. All Commercial Edition nutrient formulations are well-balanced and will provide exacting elemental ratios to the plant if used as directed.

MOLYBDENUM

Functions of Molybdenum in Plants:

  • Closely tied with nitrogen metabolism and mediates absorption of potassium.
  • Needed for proper nitrate reduction and involved in several important enzymatic reactions.
  • Directly involved in proper formation and function of several important enzymes, such as xanthine dehydrogenase, nitrate reductase, and sulfite oxidase.
  • Because of its involvement with the function of nitrate reductase, nitrogen utilization is heavily influenced by the presence of molybdenum.

Molybdenum Deficiency

Many times confused with nitrogen deficiency, molybdenum in a deficient state is extremely rare. Even though molybdenum is required by plants in exceedingly low amounts, when lacking, it is observable generally in the middle to lower region of most plants as leaf chlorosis moving from outer leaf tissue towards inner tissue. The chlorosis exhibited during molybdenum deficiency differs from nitrogen deficiency in that the chlorosis displayed appears to have hues of red, pink, and orange. Leaf tips begin to curl inwards and growth is greatly reduced as deficiency progresses. How do I correct a molybdenum deficiency? Correcting a molybdenum deficiency is easy - increase the amount of available molybdenum to the plant. This can be achieved through root feed and/or foliar application of a water-soluble molybdenum-containing fertilizer, e.g. Commercial Edition Micro nutrient or Trich-XL, ensuring that the pH is within the appropriate range for the particular system utilized (hydroponics, soil, etc.). As a side note, foliar spraying will correct a deficiency faster than root feeding - however, you must still address the cause of the deficiency within the root zone, be it an incorrect pH issue, or perhaps an unbalanced fertilizer formula.

Molybdenum Toxicity

An excessive state of molybdenum is even more rarely encountered - symptoms of a toxic state of molybdenum often appear as a copper and iron deficiency, due to molybdenum’s lock-out effect on these particular ions. How do I correct molybdenum toxicity? To rectify Molybdenum toxicity, flush root zone media with a 1/3 strength nutrient solution and then resume feeding with a more dilute/weaker mixture (approximately 3/4 strength) until problem is resolved. All Commercial Edition nutrient formulations are well-balanced and will provide exacting elemental ratios to the plant if used as directed.

CHLORIDE

Functions of Chloride in Plants:

  • Mediates stomatal opening/closing and needed for osmotic adjustment.
  • Required in photosynthetic reactions and regulates function of several enzymes.
  • Lowers the osmotic potential of leaf tissue, resulting in enhanced plant turgor.
  • Stimulates the Hill reaction in chloroplasts - necessary for O2 production.
  • Quite important counter-anion - altering potassium and sodium availability and distribution within plant tissues.

Chloride Deficiency

A deficient state of this particular nutrient (in the form of chloride) results in paling and wilting of new growth, typically developing a noticeable bronze appearance. Roots will become severely stunted and will grow quite large at the root tip. How do I correct a chloride deficiency? Correcting a chloride deficiency is easy - increase the amount of available chloride to the plant. This can be achieved through root feed and/or foliar application of a water-soluble chloride-containing fertilizer, e.g. Commercial Edition Cal-Mag, ensuring that the pH is within the appropriate range for the particular system utilized (hydroponics, soil, etc.). As a side note, foliar spraying will correct a deficiency faster than root feeding - however, you must still address the cause of the deficiency within the root zone, be it an incorrect pH issue, or perhaps an unbalanced fertilizer formula.

Chloride Toxicity

In an excessive state, plants will display a burnt appearance on new growth and begin to turn bronze in color - similar to the bronzing experienced in a deficient state. How do I correct chloride toxicity? To rectify chloride toxicity, flush root zone media with a 1/3 strength nutrient solution and then resume feeding with a more dilute/weaker mixture (approximately 3/4 strength) until problem is resolved. All Commercial Edition nutrient formulations are well-balanced and will provide exacting elemental ratios to the plant if used as directed.

SILICON

Functions of Silicon in Plants:

  • Slows the rate of transpiration and up-regulates defense genes.
  • Activates genetic plant defense mechanisms - inducer of systemic acquired resistance (SAR), bolstering plant defenses against pathogenic (pythium, botrytis, powdery mildew etc.) attack.
  • Deposits in cell walls, increasing overall plant strength, rigidity, upright stature and resistance to chewing/biting insects.
  • Critical for drought resistance - greatly reduces the production of reactive oxygen species (acid phospholipase, hydrogen peroxide, etc.) that cause oxidative damage to important cellular functional molecules, while producing many beneficial antioxidant enzymes (glutathione reductase, superoxide dismutase, etc.)

Silicon Deficiency

Regarded by many as an “essential, non-essential element” required by plants, silicon was originally considered to not be necessary for plant life. Research in recent years has shown the need for the addition of silicon to the list of essential plant nutrients, given all of the functions silicon is involved with. While discerning a silicon-deficient state is quite rare, plants lacking this particular element have noticeably weaker stems and generally droop. In addition to this, a lack of silicon makes many varietals much more susceptible to pathogenic attack and significantly reduced yields. The rate of photosynthesis can be influenced by silicon - in a deficient state newer growth will seem stunted. How do I correct a silicon deficiency? Correcting a silicon deficiency is easily rectified - increase the amount of available silicon to the plant. This can be achieved through root feed and/or foliar application of a water-soluble silicon-containing fertilizer, e.g. Commercial Edition Sila-Guard ensuring that the pH is within the appropriate range for the particular system utilized (hydroponics, soil, etc.). As a side note, foliar spraying will correct a deficiency faster than root feeding - however, you must still address the cause of the deficiency within the root zone, be it an incorrect pH issue, or perhaps an unbalanced fertilizer formula.

Silicon Toxicity

A toxic state is even more of a rarity, however. If excessive levels of silicon are present, flowers can become quite deformed. In addition to this, excessive silicon can result in quite woody stems that can break quite easily. How do I correct silicon toxicity? To rectify silicon toxicity, flush root zone media with a 1/3 strength nutrient solution and then resume feeding with a more dilute/weaker mixture (approximately 3/4 strength) until problem is resolved. All Commercial Edition nutrient formulations are well-balanced and will provide exacting elemental ratios to the plant if used as directed.